1. Field of the Invention
The present invention relates to a cooling apparatus for cooling hot objects attached thereto by vaporizing condensed liquid refrigerant.
2. Description of Related Art
A power unit cooler using boiling and condensing refrigerant has been known and used in an industrial field. Hot objects such as IGBTs attached to a heat-receiving surface of a tank containing refrigerant are cooled by evaporation latent heat of the refrigerant. The evaporated refrigerant is cooled down and condensed into liquid by radiating heat therefrom to cooling fluid such as cooling air. Since the hot objects such as IGBTs are packaged as a single unit, they can be easily attached to the unit cooler. However, if the hot objects are computer chips that are mounted on a printed board, other components mounted on the same printed board interfere with projected portions on the heat-receiving surface or on the refrigerant tank. It is, therefore, required to design the cooler unit so that no projected portions are formed on the side of the heat-receiving surface on which hot objects are attached.